Catheter adapter and process and assembly for its securance

ABSTRACT

AN ELASTIC BUSHING DISPOSED WITHIN AN ADAPTER HAS: (1) A TENSIONED CONDITION TO ENABLE ITS ASSEMBLY WITH, AND LONGITUDINAL ADJUSTMENT RELATIVE TO, A TUBE FOR SELECTIVELY ADJUSTING CATHETER LENGTH, AND (2) A NORMAL CONDITION FOR ITS SECURANCE IN AN ADJUSTED POSITION LONGITUDINALLY OF SAID TUBE.

Jan. 12, 1971 G 'Y 3,554,580

CATHETER ADAPTER AND PROCESS AND ASSEMBLY FOR ITS SECURANCE Filed Dec. 2. 1968 luvsu'roas Z5 26 34 24 Lsonnno E Govxs I CRAIG L. Bo'rr0RFF United States Patent O 3,554,580 CATHETER ADAPTER AND PROCESS AND ASSEMBLY FOR ITS SECURANCE Leonard F. Goyke, Chicago, and Craig L. Bottorlf, Evanston, Ill., assignors to Baxter Laboratories, Inc., Morton Grove, 11]., a corporation of Delaware Filed Dec. 2, 1968, Ser. No. 780,530 Int. Cl. F161 31/00 US. Cl. 285-260 7 Claims ABSTRACT OF THE DISCLOSURE An elastic bushing disposed within an adapter has: 1) a tensioned condition to enable its assembly with, and longitudinal adjustment relative to, a tube for selectively adjusting catheter length, and (2) a normal condition for its securance in an adjusted position longitudinally of said tube.

The present invention relates to catheters. Particularly the invention relates to an adapter for a catheter enabling its connection to a fitting and to a process and an assembly for securing an adapter on a catheter.

In a conventional process for catheter placement in a body space, such as for example, the lumen of a blood vessel or epidural space, admission is gained by breaching a wall defining the space with a needle having a hollow bore and an incising forward end. A catheter which customarily comprises a tube fabricated of a flexible elastomeric material with rather thin walls, then is threaded through the bore of the needle into the space. Thereafter, the needle is Withdrawn from the space by moving it longitudinally of the catheter tube, thus leaving the catheter in place. A conventional adapter such as a female luer site which is fixedly carried on an end of the tube enables connection of the catheter to a suitably fashioned hollow male fitting for communicating with a dispensing container.

In conventional practice there is a problem of effectively and economically protecting the tube from the incising end of the needle following catheter placement, because needle removal is prevented by the presence of a fixed adapter. Securing the needle to the tube and covering its incising end after needle withdrawel is an acceptable, but not an ideal expedient for preventing catheter damage.

It is an object of the present invention to eliminate the problem by providing a catheter adapter which can be attached to the catheter or tube after its emplacement in a patient and removal of the needle. An adapter enabling fulfillment of the aforesaid object comprises a hollow body having a bore extending therethrough and an end portion fashioned as a receptacle for a tubular male fitting. An elastic bushing with a passage extending therethrough is mounted within the bore and has an external surface fashioned for impinging association with the body. The bushing has a normal condition for impinging a tube in the passage and a forced condition for expanding Ighe passage to enable the adapter to be mounted on a tu e.

According to another feature of the invention an assembly enables the adapter to be adjustably mounted longitudinally of a tube. Accordingly, a catheter can be adjusted to any length desired by positioning the adapter on the catheter tube as desired and removing that portion of the catheter extending beyond the adapter. The advantage results in part from a rigid walled cannula which is removably mounted in the passage of the bushing and has a bore proportioned for enabling movement of the tube therethrough. The external diameter of the "ice cannula is larger than the diameter of the passage in the bushing and stretches it to its forced condition to enable relative adjustment thereof and the tube in the cannula. Consequently, upon removal of the cannula, the bushing expands internally and secures itself and the adapter on the tube to form a unitary assembly of an adapter and catheter.

The foregoing and other objects, features and advantages of the invention will become more apparent upon consideration of the following description and appended claims, when considered in conjunction with the accompanying drawings wherein the same reference character or numeral refers to like or corresponding parts throughout the several views in which:

FIG. 1 is an elevational view of an adapter according to the present invention prior to securance of the adapter on a tube for a catheter.

FIG. 2 is a view similar to FIG. 1 but showing an ensuing condition in the assembly of a catheter.

FIG. 3 is a view similar to FIGS. 1 and 2 but showing the adapter secured on the catheter tube.

FIG. 4 is a view of the catheter of FIG. 3 connected to a dispensing member.

FIGS. 5 and 6 are sectional views of said adapter, on a scale enlarged from the scale of FIGS. 1-4, and showing an adapter bushing variously conditioned.

Referring now more particularly to the drawings, shown in FIGS. 3 and 4 is a catheter 10 comprised of a tube 12 and an adapter 14 which is mounted on a distal portion of said tube. Exemplary catheter 10 may be for administration of fluids into a body space. To that end, the adapter has a female luer site or receptacle 16 on its rear end portion which is fashioned to receive a male luer or tubular fitting 18 (FIG. 4). The latter, which is not critical to the invention, is shown secured on the end of a fluid dispensing member 20, such as valve, for connecting tube 12 to a dispensing container (not shown).

Adapter 14 comprises an axially elongated hollow body which may be fashioned with a nose 22 (FIGS. 5 and 6) on its proximate end portion and has an axial bore 24 which extends through opposed adapter ends. An enlarged section 26 of said here comprises the receiving opening in luer site 16. It is defined by an inner surface 28 of the adapter body wall, which tapers conically forwardly, i.e., toward nose 22. A reduced section 30 of said bore extends forwardly from bore section 26 through nose 22 and generates an internal shoulder 32 between said bore sections.

A compressible or elastic bushing 34, which may be of rubber or other suitable elastomeric material, is mounted within bore section 26. The bushing has an axially extending passage 36 the normal diameter of which is less than the external diameter of tube 12. The bushing is proportioned and fashioned so that when it is disposed within the wide part of bore section 26 it is free to move. However, when it is in a narrower part it is frictionally retained within the adapter body. Accordingly, the bushing can be drawn axially from the rear end portion of the adapter toward its nose so that its external surface can be brought into impinging association with surface 28.

Bushing 34 has a normal condition for impinging tube 12 in passage 36. However, the bushing 34 also has a forced condition in which passage 36 is expanded (by means which will herein become apparent) to enable its assembly and adjustment axially of tube 12 to form the catheter.

To assemble the catheter, tube 12 may be placed in a body space by threading it through a hollow needle (not shown) which forms a passage through a body wall from the exterior into such space. Thereafter, the needle may be withdrawn from the body space and removed from g body distal end section 46 of tube 12 by displacement axially of the tube.

To enable subsequent catheter formation, that is to say, for then connecting tube 12 and adapter 14, an assembly comprising said adapter and a rigid walled cannula 38, preferably made of surgical steel, is provided. The latter member has an external diameter larger than the internal diameter of passage 36 when bushing 34 is in its normal condition, and is removably mounted in the bushing, extending through passage 36 in an axial direction. Thereby, it enlarges passage 36 and force conditions said bushing. Following assembly of the bushing an cannula, that combination is inserted in the rear of bore section 26 (as in FIGS. 1 and 5) with the cannula extending rearwardly beyond adapter 14.

The internal diameter of the cannula is adequate to facilitate easy threading therethrough of tube 12. Accordingly, following removal of the needle, as aforesaid, the tube may be moved in the direction of arrow 40 (FIG. 1) into cannula 38 through its assembly with the bushing and the adapter 14 to place the adapter in any selected relationship longitudinally of the tube.

Following, the cannula should be withdrawn from the bushing by pulling it (hand to the left of FIG. 2) from the rear end of the adapter in the direction of arrow 42 (FIG. 2). Because the bushing preferably will be loosely held in the adapter, manual retention (as with the hand shown to the right of FIG. 2) in receptacle 16 is required during cannula withdrawal.

The bushing is proportioned and fabricated in a manner such that it impinges and frictionally grips the catheter once the cannula has been withdrawn. In such'condition tube 12 and thereto secured bushing 34 can be pulled forwardly in the direction of arrow 44 from the position of FIG. 3 to the position of FIG. 6 to secure the adapter through frictional engagement with surface 28.

Receptacle 16 is proportioned in a manner such that upon association with compatibly proportined male fitting 18, the bushing will be compressed in the forward end portion of bore section 26. Such phenomenon increases the frictional force between surface 28 and the external surface of the bushing and further constricts passage 36 to more rigidly grip tube 12.

Once the adapter has been secured on the tube that portion of tubing section 46 extending beyond the adapter (to the left in FIG. 6) can be severed from the tube 12 to provide a catheter of selected length.

As many substitutions and changes could be made in the above described construction and process, and as many apparently widely different embodiments could be constructed without departing from the scope and spirit thereof, it is intendedtha-t all matter contained in the accompanying specification shall be interpreted as being illustrative and not in a limiting sense.

What is claimed is:

1. An adapter mounted on a tube for connecting said tube to a male fitting which comprises: a hollow body 'of which is tapered, and an end portion fashioned as a receptacle for a tubular male fitting, an elastic bushing with a passage extending therethrough, said bushing being secured within said tapered bore portion solely by frictional engagement therewith, a portion of said tube being disposed within said bore and extending into said passage, said tube and said bushing being secured together solely by frictional engagement therebetween resulting from constricting pressure of the inner wall of said passage against the portion of tube disposed therein.

2. An adapter according to claim 1 in which said bore has a reduced section adapted to accommodate passage of a tube and an enlarged section fashioned for retaining said bushing therein. 7

3. An adapter according to claim 2 in which said body has another end portion fashioned as a nose in axial alignment with said receptacle, said nose defining said reduced section of the bore, the remainder of said body defining said enlarged section of the bore, and a shoulder defined within said body between said reduced and enlarged sections.

4. A process comprising the steps of:

arranging an elastic bushing in a female adapter:

inserting a cannula into said bushing to enlarge a passage therein;

inserting a tube into said cannula; and thereafter removing the cannula from said 'bushing to release the tension therein and secure said adapter to said tube and frictionally securing said bushing to said adapter by moving the bushing into a restricted portion of said adapter.

5. A process according to claim 4 further characterized by the step of adjusting the adapter longitudinally, of the tube prior to removal of the cannula.

6. A process according to claim 4 in which the step of frictionally securing said bushing and said adapter is effected by compressing the bushing into frictional engagement with said adapter.

7. A process according to claim 6 characterized by inserting said cannula in the bushing to enlarge a passage therein before the bushing is arranged in the adapter.

References Cited UNITED STATES PATENTS 936,721 10/1909 Holton 285177 2,517,689 8/1950 Lement 285-177X 2,657,454 11/1953 Huyett 29450 3,096,763 7/1963 McConnaughey et al. 128-221 3,112,939 12/19'63 Graham 285374X 3,323,874 6/1967 Phillips 285423X 3,447,820 6/1969 Durnan 285-345X o DAVE W. AROLA, Primary Examiner U.S. Cl. X.R. 285345 

